1. Field of the Invention
The present invention relates to a process for the acceleration of photodegradation of polymer substances. More particularly, it relates to an effective process for the acceleration of photodegradation by which to precisely find the life of a polymer substance in the case where the polymer substance is used under usual conditions or the like.
2. Description of Related Art
In order to assess the light resistance of polymer substances, light resistant degradation test methods are currently employed using an artificial light source, such as a carbon arc lamp or a xenon lamp.
However, difficulty arises when attempting to precisely predict by these methods photodegradation of polymer substances in ordinary use conditions and this difficulty is experienced by and well known to many people. Usually, with regard to these methods conditions for the acceleration of degradation used to predict natural degradation, which are found by chance for a certain polymer substance, are not applicable at all for other polymer substances.
Therefore, because of the low reliability associated with the practice of accelerated degradation tests used to treat polymer substances under degradation-accelerated conditions to predict natural degradation, it was the usual practice to confirm the natural degradation and improve the reliability by carrying out outdoor exposure tests which require a long term.